Cleaning article

ABSTRACT

A cleaning article is provided having a top sheet disposed in a first plane; a plurality of nonwoven fabric ribbons, wherein said ribbons are stacked in a first direction, wherein said first direction is parallel to said first plane; and a seam joining said top sheet to said plurality of nonwoven fabric ribbons, wherein said seam extends in said first direction

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a cleaning article for removing contaminants such as dust or grime from a surface and is suitable for use as a disposable product.

2. Description of Related Art

Cleaning articles constructed of nonwoven fabrics are known for their propensity for trapping particulates, such as dust. These articles are commonly constructed as a disposable wipe or mop that can be applied to a surface to be cleaned. U.S. Pat. No. 6,813,801, for example, discloses a cleaning brush having dust collecting fibrous midsection sandwiched between two layers of fabric strips that provide a degree of rigidity to the article. EP 0 923 902 discloses a dust-collecting cleaning brush having a base layer attached to one or more layers of filaments or bundled split yarns.

However, there remains a need for an improved cleaning article with superior dust collection performance that also can be simply and inexpensively produced. This invention satisfies these needs among others.

SUMMARY OF THE INVENTION

The present invention, in part, provides a cleaning article, such as disposable wipe, mop, or the like, having a top sheet attached to a plurality of nonwoven ribbons, the surface of which are rotated 90° with respect to the surface of the top sheet. These articles are not only very economical to produce, but also have superior cleaning ability compared to other cleaning articles.

The orienting the nonwoven ribbons orthogonally to the attached top sheet, provides many improvements over other known cleaning devices. For example, when the device is wiped over a surface to be cleaned, the ribbons fan out and partially overlap. This increases the article's contact surface area compared to wipe or mops with tangled filaments, which in turn, increases the article's cleaning performance. Importantly, the orientation of the ribbons with respect to the top sheet also improves the article's cleaning capacity because this orientation reduces entanglement of the ribbons and assists in maintaining the original form of the article during use. The orientation of the ribbons also provides improved cleaning performance along the edge of the article which is useful when removing dust from corners, etc.

Accordingly, an aspect of the present invention provides a cleaning article comprising (a) a top sheet disposed in a first plane; (b) a plurality of nonwoven fabric ribbons, wherein said ribbons are stacked in a first direction, wherein said first direction is parallel to said first plane; and (c) a seam joining said top sheet to said ribbons, wherein said seam extends in said first direction.

In another aspect, provided is a method for producing a cleaning device comprising: (a) stacking a plurality of nonwoven fabric sheets in a first direction; (b) cutting said plurality of nonwoven fabric sheets in said first direction to form a plurality of stacks of nonwoven fabric strips; and (c) attaching a nonwoven fabric top sheet to at least one of said stacks of nonwoven fabric strips along said first direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the top view of a wipe according to a preferred embodiment of the invention;

FIG. 2 shows the bottom view of the wipe in FIG. 1;

FIG. 3 shows a detailed view of the wipe in FIG. 2; and

FIG. 4 shows a side view of the wipe in FIG. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Turning to FIG. 1, shown is a cleaning article 1 according to an embodiment of the invention. Here, the cleaning article comprises a top sheet 10 and a plurality of ribbons 20 constructed of one or more nonwoven materials that are stacked in a direction 28 parallel to the top sheet 10 and are attached to the top sheet at a seam 30.

As used herein, the term “cleaning article” refers to a wipe-, brush-, or mop-type device that is intended to be used for cleaning, wiping, or sweeping purposes.

As used herein, the term “ribbon” means a long, narrow strip or band of material having a major top surface and a major bottom surface.

The term “stack” means an orderly arrangement of the ribbons, each directly on top of the last, in the form of layers. That is, the ribbon surfaces are oriented with respect to each other so that the bottom surface of one ribbon is on top of, and is in contact with, the top surface of an adjacent, second ribbon, and that the bottom surface of the second ribbon is on top of, and is in contact with, the top surface of an adjacent, third ribbon, and so on. The direction of stacking corresponds to a line perpendicular to the plane of the major surfaces of the stacked ribbons.

As used herein, the terms “top” and “bottom” only indicate a relative spatial arrangement and do not necessarily correspond to a vertical relationship or spacing.

As used herein, the term “seam” means a more or less straight line, ridge, or similar feature defining a junction between two or more pieces of material.

As used herein, the term “contact surface area” means the surface area of the cleaning device available to for contacting the surface of an article to be cleaned.

As used herein, the term “distal ends” with respect to a ribbon means the ends of the ribbon that are distal relative to the seam.

The ribbons of the device cumulatively provide a large surface area for contacting an article to be cleaned and removing dust and/or grime on that article. Accordingly, the ribbons are preferably sized and arranged in the device to facilitate the collection of particulates, such as dust, and/or other grime such as grease and dirt. To achieve a good cleaning effect, the ribbons preferably fan out from the seam and are oriented so that the major surfaces of the distal ends of the ribbons can rest on, or be pressed against, the contoured surface of the article to be cleaned without substantial overlap or tangling of individual ribbons with each other. It has been discovered that stacking the ribbons so that their plane of their major surfaces are oriented about 90° from the plane of the top sheet unexpectedly improves the distribution and coverage of the device when used for dusting or wiping surfaces. That is, stacking the ribbons as described herein decreases the likelihood that individual ribbons will become entangled with each other compared to, for example, bundled filaments, thus increasing the cleaning capacity of the device.

Stacking the ribbons as described herein also improves the contact surface area of the cleaning device because the major surfaces of the ribbons tend to rotate and become staggered as they fan out from the seam. Preferably, the rigidity of the ribbon is low enough so that the distal ends 22 can easily bend or rotate. Accordingly, some, and preferably a majority, of the ribbons have a distal end 24 that is in a plane that is rotated between about 1 and about 90 degrees from the plane of a portion of the ribbon 26 proximal to the seam. (See FIG. 3.) This bending and rotating also allows the ribbons to fan out 27 as they extend from the seam. (See FIG. 4.) As the distal ends of the ribbons fan out, their major surfaces become overlapped so that the leading edge of ribbon is either ahead of or behind the leading edge of an adjacent ribbon. The staggering provides a more continuous contact between the ribbons and the surface of the article to be cleaned as the cleaning device is wiped over the surface of the article, which in turn, increases the article's cleaning capacity.

Moreover, arranging the ribbons in a stack improves the device's shape retention when exposed to an external compression force, such as the force exerted upon the device when it is used for wiping or moping. Accordingly, as shown in detail in FIG. 2, the ribbons are stacked in a first direction 28 that is parallel to the plane 12 of the top sheet and parallel to the direction 32 of the seam 30.

Between the distal ends 22 of the ribbon is the seam 30. As shown in FIG. 1, the ends of the stacked ribbons preferably extend beyond the top sheet. Preferably, each of the ribbons of the stack have a similar length and also have a similar width. That is, preferably, the ribbons are of a uniform size and are stacked so that ribbons for a straight column or row. In certain preferred embodiments, the ribbons have a length of about 3 to about 30 cm, more preferably about 6 to about 18 cm, and even more preferably about 10 to about 14 cm. In certain preferred embodiments, the ribbons have a width of about 0.05 to about 5 cm, more preferably from about 0.1 to about 1 cm, and even more preferably about 0.3 to about 0.6 cm. In certain highly preferred embodiments, the ribbons have a length to width ratio of about 10 to about 40, more preferably from about 15 to about 35 and most preferably from about 20 to about 30. In certain embodiments, the ribbons have a thickness of about 0.1 to about 3 mm, more preferably from about 0.5 to about 2 mm, and even more preferably about 0.75 to about 1.25 mm.

In certain embodiments, each ribbon is constructed of a single ply or layer of the same nonwoven material. In other embodiments, each ribbon is constructed of two or more plies or layers of different nonwoven materials or a nonwoven material and another material, such as a paper or film. These multiple plies can be bound or otherwise attached over a majority of the ribbon so that the major top surface of the ribbon is a first nonwoven material and the major bottom surface is a second nonwoven material, or the plies or layers may be attached or otherwise bound at one or more discrete points along the ribbon. In certain embodiments, the stack of ribbons can comprise a ribbons of different materials stacked in an alternating, repeating, or random sequence. For example, in one embodiment, the stack of ribbons comprises alternating nonwoven ribbons and plastic film ribbons.

Preferably, at least a portion of the ribbons are constructed of a nonwoven material. More preferably, a majority of the ribbons are constructed of a nonwoven material, and most preferably all of the ribbons are constructed of a nonwoven material. In certain embodiments, the nonwoven comprises meltblown or spunblown fibers of a thermoplastic, preferably a polyolefin. Examples of preferred thermoplastics include polyethylene, polypropylene, polybutene, polyethylene terephthalate, polymethyl pentene, polychloro-trifluoroethylene, polyamide, polyester, polycarbonate, polysulfon, polyether sulfon, polyphenylene sulfide, polyacryl nitrile, polyvinyl chloride, polystyrene, polyaryl ether keton, polyvinylene fluoride, polyoxy methylene, polyurethane, or copolymers or mixtures thereof. Polypropylene is a preferred polyolefin.

In certain embodiments, the nonwoven material of the ribbons is selected for high liquid absorbency for cleaning wet surfaces. For embodiments directed to removing aqueous-based contaminants or spills from the surface of an article to be cleaned, the ribbons are constructed of a hydrophilic nonwoven material. For embodiments directed to removing non-aqueous, liquid contaminants or spills from the surface of an article to be cleaned, the ribbons are constructed of a hydrophobic nonwoven material. For embodiments directed to removing non-particulate grim from the surface of an article to be cleaned, the ribbons are constructed of a nonwoven material, preferably a hydrophilic nonwoven material, and are soaked in a cleaning solution.

In certain embodiments, the nonwoven material of the ribbons is selected for its ability to trap dust. Preferably, these nonwoven ribbons are electrostatically charged to improve its dust holding capacity. Various electrostatic charging techniques, such as corona treatment, may be employed to charge the nonwoven. One such method involves a charging device having multiple thin tungsten wires laid across the grounded curved heated plate and connected with the negative terminal of a voltage source. The device sprays a negative charge on to the top of the nonwoven by means of the corona effect as the nonwoven is drawn past the device. Preferably, the wires are placed towards the beginning of the plate. Although this arrangement leads to partial discharging of the nonwoven as it travels further across the heating plate, the charges lost are primarily those that are the least stable. Thus, this arrangement thermally ages the nonwoven so that most of the remaining charges are embedded in a very stable manner. As a result, the remaining charge of the nonwoven has an exceptionally high persistence at ambient temperature. In fact, the thermal stability of the charge that is left is also increased. Moreover, the stability of the electrostatic charge against moisture is considerably improved.

Another method for charging a nonwoven involves passing the nonwoven about midway in a gap of about 1.5 to 3 inches between two DC corona electrodes. Corona bars with emitter pins of metallic wire may be used in which one corona electrode has a positive DC voltage potential of about 20 to 30 kV and the opposing electrode has a negative DC voltage of about 20 to 30 kV.

Other preferred methods of charging a nonwoven include the two electrostatic charging techniques described in U.S. Pat. No. 5,401,446 (Tsai). The first technique involves suspending the nonwoven on insulated rollers as the nonwoven passes around the inside circumference of two negatively charged metal shells with a positive corona wire for each shell. Generally, about 1000 to about 3000 positive volts are imparted on one side of the nonwoven with a similar magnitude of negative volts imparted on the other side of the nonwoven.

The second technique involves contacting the nonwoven with a metal roller having a DC voltage of about −1 kV to about −10 kV and a wire having a DC voltage of about +20 kV to about +40 kV disposed about 1 to about 2 inches above the negatively biased roller. Each side of the nonwoven is exposed in succession to this roller/wire charging configuration. About 300 to about 1500 volts are imparted on each side of the nonwoven, each side having an opposite polarity. The higher surface potentials obtained by this technique, however, have not been found to result in better measurable filtration efficiencies of webs made from the nonwoven. Therefore, the first technique is preferred because it is easier and more economic to treat the nonwoven.

The nonwoven material may be electrostatically charged either before or after it is formed into a ribbon.

When used to collect dust or otherwise clean the surface of an article, the cleaning device is preferably oriented so that the ribbons are in contact with the article and are between the article and the top sheet. The top sheet, in turn, can serve as an interface between the ribbons and the user and/or an attached secondary device used to facilitate dust collection. For example, the top sheet can be of a shape and size and be constructed of a material suitable for a user's grasp or for a user to hold or press against while wiping the article. The shape and size and materials of construction of the top sheet also can be adapted to receive an extension device, such as a wand or pole, and/or adapted to be removably attached to a handle. For example, the embodiment shown in FIG. 1 comprises a top sheet 10 constructed of two layers of nonwoven material, wherein the first layer 12 is directly on top of the second layer (not shown). The seam 30 traverses both layers of the top sheet as well as the ribbons. The two layers are attached at multiple points long two additional lines 14 so that two pockets are formed in the top sheet that can receive a two-prong handle, wand, or pole.

Suitable materials for top sheet include plastic film, dry or wet-laid paper, woven material, nonwovens, or some combination thereof. Examples of plastic films include cellophane and other cellulose-based films, as well as films made from thermoplastic polymers, preferably polyolefins, such as high, medium, or low density polypropylene or polyethylene, isoprenes, styrene, and blends comprising one or more of these. Examples of woven materials include textile, netting, or scrim woven from a rayon or other cellulose-derived fiber, natural fiber, such as cotton, or synthetic fiber such as polyester, polypropylene, polyethylene, and the like. Examples of nonwovens that are suitable for the top sheet include those described above. Preferably, the top sheet is not statically charged.

The size of the top sheet is not particularly limited. However, it is preferable that the length of the top sheet is approximately the length of the stack of ribbons. Also, it is preferably that the width of the top sheet is less than the length of the ribbons. In certain embodiments, the ratio of the length of the ribbons to the width of the top sheet is 1.25 to about 4, more preferably from about 1.5 to about 3, and even more preferably from about 1.75 to about 2.5.

In certain embodiments, such as the one shown in FIG. 2, the cleaning device comprises a base sheet 40 disposed so that the ribbons 20 are between the base sheet and the top sheet. These embodiments are preferred because they tend to secure the ribbons in the device compared to embodiments without a base sheet. Preferably, the seam 30 extends from or through the base sheet 40, through the ribbons 20, and to or through the top sheet. Preferably, the base sheet is constructed of one or more of plastic film, dry or wet-laid paper, woven material, and nonwovens as described herein. The top and bottom sheets may be the same material or different materials.

The length of the base sheet is preferably about the same length of the top sheet. However, the width of the base sheet is preferably less than the top sheet so that the base sheet does not overly obstruct the ribbons from directly contacting the article to be cleaned. Preferably, the width of the base sheet is sufficient to facilitate a strong seam and preferably less than 2 cm. More preferably, the width is from about 0.2 to about 2 cm, more preferably from about 0.5 to about 1.5 cm, and even more preferably from about 0.75 to about 1.25 cm.

The method of forming the seam of the cleaning device is not particularly limited provided that the seam is suitable for a disposable cleaning device and is can secure the ribbons to the top sheet during a conventional dusting activity. Examples of suitable seams include stitching, a thermal bond, an ultrasonic bond, or an adhesive bond. Preferably, the seam is stitching.

In another embodiment, provided is a method for producing a cleaning device comprising (a) stacking a plurality of nonwoven fabric sheets in a first direction; (b) cutting said plurality of nonwoven fabric sheets in said first direction to form a plurality of stacks of nonwoven fabric strips; and (c) attaching a nonwoven fabric top sheet to at least one of said stacks of nonwoven fabric strips along said first direction. In certain preferably embodiments, sheets of material are stacked and then cut to form a plurality of stacks of ribbons. The stacks are then separated from each other and sewn or otherwise bonded to a top and base sheet. In other embodiments, a plurality of individual ribbons are formed and then stacked. This stack is then sewn or otherwise bonded to a top and base sheet. 

1. A cleaning article comprising: a. a top sheet disposed in a first plane; b. a plurality of nonwoven fabric ribbons, wherein said ribbons are stacked in a first direction, wherein said first direction is parallel to said first plane; and c. a seam joining said top sheet to said plurality of nonwoven fabric ribbons, wherein said seam extends in said first direction.
 2. The cleaning article of claim 1 wherein at least a portion of said ribbons are each at least partially disposed in separate planes that are perpendicular to said first plane.
 3. The cleaning article of claim 1 wherein each of said ribbons has a major length defining a first end and a second end of the ribbon and wherein said seam is disposed between said first and second ends of the ribbons.
 4. The cleaning article of claim 3 wherein said top sheet has a minor length defining a first and second end of the top sheet wherein said seam is disposed between said first and second ends of the top sheet.
 5. The cleaning article of claim 4 wherein the distance from the seam to the first ends of the ribbons is greater than the distance from the seam to the first end of the top sheet and the distance from the seam to the second ends of the ribbons is greater than the distance from the seam to the second end of the top sheet.
 6. The cleaning article of claim 1 further comprising a base sheet, wherein said stacked ribbons are disposed between said base sheet and said top sheet and said seam joins said stacked ribbons to said base sheet and said top sheet.
 7. The cleaning article of claim 1 wherein said plurality of nonwoven fabric ribbons comprise ribbons constructed of a first nonwoven material and ribbons constructed of a second nonwoven material that is different from said first nonwoven material.
 8. The cleaning article of claim 1 wherein at least a portion of said nonwoven fabric ribbons are constructed of polyolefin filaments.
 9. The cleaning article of claim 8 wherein said polyolefin is selected from the group consisting of polyethylene, polypropylene, polybutylene, polyester, and copolymers thereof.
 10. The cleaning article of claim 1 wherein at least a portion of said nonwoven fabric ribbons are constructed of meltblown polyolefin.
 11. The cleaning article of claim 1 wherein at least a portion of said nonwoven fabric is electrostatically charged.
 12. The cleaning article of claim 1 wherein said seam comprises at least one of thermomechanical bond, ultrasonic bond, adhesive bond, and mechanical fastener.
 13. The cleaning article of claim 12 wherein said seam comprises stitching.
 14. The cleaning article of claim 1 wherein said top sheet is selected from the group consisting of plastic film, nonwoven fabric, or dry or wet-laid paper.
 15. The cleaning article of claim 1 wherein said top sheet is a nonwoven fabric.
 16. The cleaning article of claim 1 wherein said article further comprises a cleaning solution and wherein said ribbons are wetted with said cleaning solution.
 17. A cleaning article comprising: a. a top sheet; and b. a plurality of adjacent nonwoven strips, wherein each strip has two major surfaces forming opposite sides of the strip, wherein each strip is disposed so that at least a portion of one of the major surfaces of the strip faces a respective major surface of an adjacent strip; and wherein the plurality of adjacent nonwoven fabric strips is attached to the nonwoven fabric top sheet.
 18. A method for producing a cleaning device comprising: a. stacking a plurality of nonwoven fabric sheets in a first direction; b. cutting said plurality of nonwoven fabric sheets in said first direction to form a plurality of stacks of nonwoven fabric strips; and c. attaching a top sheet to at least one of said stacks of nonwoven fabric strips along said first direction. 